Modifying the polymer-filler interface is an efficient strategy to enhance the gas separation performance of zeolite-filled mixed matrix membranes (MMMs) by overcoming the interfacial defects. In this study, zeolite 13X particles were modified with 3-aminopropyl(diethoxy)methylsilane (APDEMS) and subsequently embedded into the synthesized 6FDA-Durene polyimide (PI) to prepare MMMs. The characteristic properties of modified zeolite particles and fabricated MMMs were investigated via FTIR, XRD, BET, DLS and SEM analyses. Moreover, the separation performance of resultant membranes was studied for CO2/N2 separation considering filler content (0–20 wt.%) at different feed pressure in the range of 0.2 to 1 MPa. The best separation performance was obtained by embedding 15 wt.% of aminosilanized zeolite 13X (ASZX) into the PI membrane that exhibits the excellent CO2 permeability of 887 Barrer and CO2/N2 selectivity of 25.3 at the feed pressure of 0.2 MPa. These values increased by about 95% and 81%, respectively compared to those for pure PI membrane. In addition, the thermomechanical properties of MMMs were improved after aminosilane modification of zeolite particles. Surface modification of the zeolite particles via the aminosilane coupling agents can be considered as a suitable strategy to improve filler/polymer interfacial adhesion which consequently increases the CO2 adsorption through the CO2-amine interactions.
